一、二阶海杂波谱仿真图------------------------%%-------------------线性调频连续波发射信号仿真------------------------------%clc;clear all;close all;%---------------------初始参数设置-----------------------------------------%T = 0.25; % 脉冲宽度(即脉冲重复周期)TT =64; % 相干积累时间N = TT/T; % 相干积累时间内的脉冲数% Fs = B*2; % 采样频率saNum = 5; % 每个周期的采样点数Ts = T/saNum; % 采样间隔sig_ran = 60; % 目标所在的距离单元Fs = 10e2; %--------------------------------发射信号仿真------------------------------%tt = Ts:Ts:T;t = 0:1/(Fs):TT;%--------------------------------海杂波信号仿真-----------------------------%%------------------------------------第一种--------------------------------%% 一阶海杂波f0 = 18e6; % 雷达载频g = 9.8; % 重力加速度c = 3e8;lambda = c/f0; % 电磁波波长alfa = 8.1e-3;beita = 0.74;U = 25; % 待变参数，海面上19.5m处的风速kc = g/U^2 ; %截止波束theta = 180; % 雷达波束方向到海浪波列前进方向的转角fi = 0; % 雷达波束方向的方位角% theta+fi %表示海浪波列前进方向的方位角fw= 90; %海面风向的方位角k0 = 2*pi/lambda;fd1 = 0.1012 * (f0/1e6)^0.5; % 一阶Bragg峰的多普勒频率,存在洋流时偏移fd2 = -fd1;S1 = 0.005*(-2*k0)^-4*exp(-0.74*(kc/(2*k0))^2);% 两个Bragg峰的幅度不同(随海面风向的方向角)S2 = 0.005*(-2*k0)^-4*exp(-0.74*(kc/(2*k0))^2);% 两个Bragg峰的幅度不同(随海面风向的方向角)G1_1 = 4/(3*pi)*(cos((180-fw)*pi/180/2))^4;G2_1 = 4/(3*pi)*(cos((0-fw)*pi/180/2))^4;Bragg1_1 = 2^6*k0^4*pi*S1*G1_1*exp(2*pi*1i*fd1.*t).*exp(-(t).^2./((2^2)*0.4))./((2*pi)^0.5*0.4); % 正轴一阶Bragg峰Bragg1_2 = 2^6*k0^4*pi*S2*G2_1*exp(2*pi*1i*fd2.*t).*exp(-(t).^2./((2^2)*0.4))./((2*pi)^0.5*0.4); % 负轴一阶Bragg峰% Noise= 1.2358e-004*randn(1,length(t));%2^9也行freq = linspace(-Fs/2,Fs/2,length(t));B_1 = fftshift(abs(fft(Bragg1_1+Bragg1_2)));% B_11 = B_1/max(B_1);% B_11 = 20*log10(B_11);% figure(1);% plot(freq,B_11); %一阶bragg峰% xlim([-2 2]);% 二阶海杂波f4 = linspace(-1.1*fd1,-2*fd1,20);f3 = linspace(-0.9*fd1,-0.1*fd1,80);f1 = linspace(0.1*fd1,0.9*fd1,80);f2 = linspace(1.1*fd1,2*fd1,20);delta_k = k0/40;delta = 0.011 - i*(0.0121);for n = 1: k_n = n*delta_k; for i = 1:length(f1) %m=-1,m^=1% if k_n-2*k0< k_p < k_n+2*k0 theta = linspace(0,180,181); k_p = (2*pi*f1(i)+(g*k_n)^0.5)^2/g;% theta_1 = acos((k_p^2-k_n^2-4*k0^2)/4*k_n*k0); theta_2 = asin(k_n*sin(k_n*sin(theta.*pi/180)./k_p))-pi; kafang1 = -i*0.5*(k_n+k_p-k_n*k_p*((2*pi*f1(i))^2+(2*pi*fd1)^2)/(k_n*k_p)^0.5/((2*pi*f1(i))^2-(2*pi*fd1)^2)); kafang2 = 0.5*(k_n*k0*-cos(theta.*pi/180).*(k_p*k0*-cos(theta_2.*pi/180))./k0^3/delta); kafang = (abs(kafang1+kafang2)).^2*2^6*k0^4*pi*n*(delta_k^2); S1 = 0.005*(-k_n).^-4*exp(-0.74*(kc/(-k_n))^2);% 两个Bragg峰的幅度不同(随海面风向的方向角) S2 = 0.005*(k_p).^-4*exp(-0.74*(kc/(k_p))^2);% 两个Bragg峰的幅度不同(随海面风向的方向角) G1 = 4/(3*pi)*(cos((theta-fw).*pi/180/2)).^4; G2 = 4/(3*pi)*(cos((theta_2-fw).*pi/180/2)).^4; X(i) = trapz(kafang.*G1.*G2.*S1.*S2,theta.*pi/180); theta = linspace(-180,0,181); k_p = (2*pi*f1(i)+(g*k_n)^0.5)^2/g;% theta_1 = acos((k_p^2-k_n^2-4*k0^2)/4*k_n*k0); theta_2 = asin(k_n*sin(k_n*sin(theta.*pi/180)./k_p))+pi; kafang1 = -i*0.5*(k_n+k_p-k_n*k_p*((2*pi*f1(i))^2+(2*pi*fd1)^2)/(k_n*k_p)^0.5/((2*pi*f1(i))^2-(2*pi*fd1)^2)); kafang2 = 0.5*(k_n*k0*-cos(theta.*pi/180).*(k_p*k0*-cos(theta_2.*pi/180))./k0^3/delta); kafang = (abs(kafang1+kafang2)).^2*2^6*k0^4*pi*n*(delta_k^2); S1 = 0.005*(-k_n).^-4*exp(-0.74*(kc/(-k_n))^2);% 两个Bragg峰的幅度不同(随海面风向的方向角) S2 = 0.005*(k_p).^-4*exp(-0.74*(kc/(k_p))^2);% 两个Bragg峰的幅度不同(随海面风向的方向角) G1 = 4/(3*pi)*(cos((theta-fw).*pi/180/2)).^4; G2 = 4/(3*pi)*(cos((theta_2-fw).*pi/180/2)).^4; Y(i) = trapz(kafang.*G1.*G2.*S1.*S2,theta.*pi/180); %m=1,m^=-1 theta = linspace(0,180,181); k_p = (2*pi*f1(i)-(g*k_n)^0.5)^2/g;% theta_1 = acos((k_p^2-k_n^2-4*k0^2)/4*k_n*k0); theta_2 = asin(k_n*sin(k_n*sin(theta.*pi/180)./k_p))-pi; kafang1 = -i*0.5*(k_n+k_p-k_n*k_p*((2*pi*f1(i))^2+(2*pi*fd1)^2)/(k_n*k_p)^0.5/((2*pi*f1(i))^2-(2*pi*fd1)^2)); kafang2 = 0.5*(k_n*k0*-cos(theta.*pi/180).*(k_p*k0*-cos(theta_2.*pi/180))./k0^3/delta); kafang = (abs(kafang1+kafang2)).^2*2^6*k0^4*pi*n*(delta_k^2); S1 = 0.005*(k_n).^-4*exp(-0.74*(kc/(k_n))^2);% 两个Bragg峰的幅度不同(随海面风向的方向角) S2 = 0.005*(-k_p).^-4*exp(-0.74*(kc/(-k_p))^2);% 两个Bragg峰的幅度不同(随海面风向的方向角) G1 = 4/(3*pi)*(cos((theta-fw).*pi/180/2)).^4; G2 = 4/(3*pi)*(cos((theta_2-fw).*pi/180/2)).^4; A(i) = trapz(kafang。